JPH10111681A - Bent and formed parts of grand piano - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a manufacturing cost while assuring good bending formability by constituting part of plural sheets of wooden board materials superposed and adhered on and to each other of plywood and bending and forming the laminate so as to meet the outer peripheral shape of a grand piano. SOLUTION: The inner rim of the grand piano comprises plural sheets of the wooden board materials 2 superposed on each other. The respective wooden board materials 2 comprises the plywood of three plies consisting of lauan, etc., i.e., one sheet of veneer 2a for a core and two sheets of the decorative veneers 2a, 2b respectively adhered to the front and rear thereof. For example, the thickness ta of the veneer 2a for the core is specified to 2.0mm and the thickness TB of the respective decorative veneers 2b to 0.5mm. The thickness over the entire part of one sheet of the plywood is specified to 3.0mm. The veneer 2a for the core and the decorative veneers 2b respectively consist of rotary veneers. While the figured grains of the respective decorative veneers 2b extend in the longitudinal direction of the inner rim, the figured grains of the veneer 2a for the core extend to intersect orthogonally therewith, i.e., in the transverse direction of the inner rim.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bent product of a grand piano which is bent and shaped so as to conform to the outer peripheral shape of a grand piano, and more particularly, to a stack or a side plate.

[0002]

2. Description of the Related Art The stacking of a grand piano constitutes a part of a back mechanism and serves as a base for mounting a side plate. The side plate is adhered along the outer periphery of the stack to form a part of an exterior. Each has a curved shape that matches the outer shape of the grand piano.

[0003] Conventional stacking and side panels are generally formed by stacking and bonding a plurality of wooden veneers. In addition, since the structure is basically the same in such a stacking and a side plate, hereinafter, as a representative,
The configuration of the conventional loading will be described with reference to FIG. As shown in FIG. 1A, the wooden veneers constituting the stack 11 are each composed of a predetermined number of A-type wooden veneers 11a and B-type wooden veneers 11b, which are alternately arranged. It is designed to be stacked.

The A-type wood veneer 11a is composed of a single continuous rotary veneer obtained by subjecting Rawan or the like to rotary processing so that the wood grain extends in the length direction of the pile 11 and has a thickness of 1 mm. It is about 3 mm. On the other hand, the B type wood veneer 11b is made of a plurality of veneer materials 11 obtained by cutting a wood veneer having the same material and thickness as the A type into a predetermined length.
c has a divided configuration in which the stacking 11 is arranged in the length direction. In this case, the grain of each veneer material 11c is orthogonal to the grain of the A-type wood veneer 11a, that is, the loading 1
1 to extend in the width direction. Further, the space between the joints of the two adjacent veneers 11c, 11c is temporarily fixed with a paper tape (not shown) or the like. Then, these two types of wooden veneers 11a and 11b are alternately stacked while applying an adhesive, and are pressed by a press molding machine (not shown) to thereby obtain a thickness as shown in FIG. It is bent and formed into a stack 11 having a curved shape of about 45 mm.

As described above, the loading 11 is composed of the two types of wood veneers 11a and 11b. First, the wood type veneer having the grain extending in the length direction of the loading 11 is used. By using 11a, the bending strength at the time of bending the stacking 11 is ensured. On the other hand, the A type wood veneer 11a alone has too large bending stiffness, and it is easy for bending failure to occur particularly at a place where the curvature of the pile 11 is large, so that the grain of the B type extends in the width direction of the side plate 11. By using the wood veneer 11b together, the bending rigidity is reduced,
This is to facilitate bending. For the same reason, the B-type wood veneer 11b is divided into a plurality of veneers 11c.

[0006]

However, since the above-described conventional loading 11 uses a high-priced wooden veneer as a constituent plate, the material cost increases. In addition, for the wood type veneer 11b of the B type, the wood veneer is cut into a plurality of veneer materials 11c of a predetermined length and arranged, and pre-processing such as temporary fixing between the veneer materials 11c, 11c with paper tape or the like. Is required, the processing cost is also increased, and the manufacturing cost of the entire stack 11 is increased. This is the same also about the conventional side plate comprised similarly to the loading 11.

The present invention has been made in order to solve such problems, and provides a bent product of a grand piano that can reduce manufacturing costs while ensuring good bending formability. The purpose is to:

[0008]

In order to achieve this object, the present invention comprises a plurality of wooden boards stacked and bonded to each other, and formed by bending to conform to the outer shape of the grand piano. And wherein at least one of the plurality of wooden boards is made of plywood.

According to this bent product of a grand piano, at least one of the plurality of wood plates constituting the same is made of plywood, and for example, a commercially available plywood is used as the plywood. As a result, the material cost is reduced as compared with the conventional case where all the wooden boards are made of a wooden veneer. Also, plywood is originally formed by stacking the wood grain so as to intersect with each other, so that it has a certain degree of bending strength and is better than wood veneer when the wood grain extends in the length direction of the bent molded product. And the bending rigidity is small. Therefore, by forming at least one of the plurality of wooden board members from plywood, the bending rigidity can be reduced by that amount, so that good bending formability can be obtained. As a result, it is possible to produce a wooden board only by cutting the plywood to a predetermined size, and it is not necessary to perform pre-processing such as cutting or temporary fixing of the veneer 11c which has been performed during the manufacture of the conventional stacking 11. Therefore, the processing operation can be simplified and the processing cost can be reduced accordingly.

[0010] In this case, it is preferable that all of the plurality of wood boards are each made of plywood.

[0011] In this configuration, as a plurality of wooden board materials,
Since all plywood is used, material costs and processing costs can be significantly reduced.

In these cases, the plywood has one core veneer whose grain extends in a direction perpendicular to the direction along the outer periphery of the grand piano, and each has a smaller thickness than the core veneer. Preferably, the core veneer is formed of two veneer veneers that are adhered to the front and back surfaces of the veneer veneer and have a grain extending in a direction along the outer periphery of the grand piano.

According to this configuration, the plywood is composed of a three-ply plywood consisting of one core veneer and two decorative veneers on the front and back. Such a three-ply plywood is particularly common, inexpensive and easily available among commercially available plywoods, so that a bent product can be manufactured at a lower cost. In addition, the wood grain of each veneer veneer with a small thickness extends in the direction along the outer periphery of the grand piano, thereby ensuring the required bending strength and a core having a thickness greater than the veneer veneer. The grain of the veneer veneer extends in a direction perpendicular to the direction along the outer circumference of the grand piano,
Since the degree of reduction in bending stiffness is increased, good bending formability is obtained.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 2 shows the stacking of a grand piano to which the present invention is applied, before and after bending. As shown in FIG. 1A, a plurality of sheets (for example, 15 sheets) stacked on each other are stacked.
(Only four sheets are shown).

As shown in FIG. 1, each wooden board 2 is made of 3-ply plywood made of Lauan or the like.
Two core veneers 2a and two
The decorative veneer is composed of two decorative veneers 2b and 2b.
For example, the thickness ta of the core veneer 2a is 2.0 mm, the thickness tb of each veneer veneer 2b is 0.5 mm, and the total thickness t of one plywood is 3.0 mm.

The veneer veneer 2a and the decorative veneer 2b
Consists of a rotary veneer, and each veneer veneer 2b
The wood grain extends in the length direction of the stacking 1, whereas the wood grain of the core veneer 2a extends in a direction perpendicular to this, that is, in the width direction of the stacking 1. Plywood with the above configuration is also commercially available, inexpensive, and easily available.
By simply cutting such a plywood to a predetermined size, the wooden board 2 can be formed at low cost and easily.

The plurality of wooden boards 2 having the above structure are
In a state of being stacked while applying the adhesive, it is inserted between the dies of a press molding machine (not shown) and pressed to form a curved shape matching the outer shape of the grand piano as shown in FIG. It is formed into a stack 1 with a thickness of about 45 mm.

As described above, in the unloading 1 of the present embodiment, since the wooden board 2 which is the constituent board is entirely made of 3-ply plywood, these are all made of wood veneer. Material costs can be greatly reduced as compared with the stacking of materials. Also, in this plywood, the required bending strength is ensured because the grain of the veneer veneer 2b having a small thickness extends in the length direction of the stacking 1. Furthermore, since the grain of the core veneer 2a, which is thicker than the veneer veneer 2b, extends in a direction orthogonal to the veneer veneer, the degree of reduction in bending rigidity is increased, so that good bending formability is obtained. Therefore, even at a location having a large curvature such as the vicinity of points A, B, and C in FIG. As a result, it becomes possible to produce the wooden board 2 only by cutting a commercially available plywood into a predetermined size, and to perform pre-processing such as cutting or temporary fixing of the veneer 11c which has been performed at the time of manufacturing the conventional loading 11. Is unnecessary, so that the processing cost can be reduced by simplification of the processing operation, and the manufacturing cost of the loading 1 can be significantly reduced together with the reduction of the material cost.

A support, a frame, and a soundboard (none of which are shown) are attached to the bending-formed stack 1, which constitutes a back mechanism of a grand piano, and as shown in FIG. A similar curved side plate 3 is adhered along the outer peripheral surface of the stack 1. This side plate 3 has a thickness of, for example, about 20 mm, and is not shown, but is made of a plurality of (for example, 7) wooden boards made of 3-ply 3 mm-thick plywood similarly to the above-described loading 1. And
These are stacked and bent by a press forming machine, so that they are manufactured separately from the loading 1. Therefore, the same effect as the above-described loading 1 can be obtained for the side plate 3 as well.

In order to compensate for the lack of precision in the bending by the press forming machine, if necessary, the bonding surface between the stack 1 and the side plate 3, for example, the outer peripheral surface of the stack 1 is cut by a moulder. Will be Further, in order to omit such a molding process, the loading 1 and the side plate 3 may be simultaneously bent.

The present invention can be implemented in various modes without being limited to the embodiments described above. For example, in the embodiment, the plurality of wooden boards constituting the stacking and the side boards are all made of plywood. Part of the wood board may be plywood, and the rest may be wood veneers in the same manner as in the related art, whereby material costs can be reduced for the replacement of plywood. In addition, the number of plywoods, the thickness of each plywood, and the stratigraphy and thicknesses of the core veneer and decorative veneer constituting the plywood can also be appropriately changed. In addition, it is possible to change the detailed configuration and the like without departing from the spirit of the present invention.

[0022]

As described above, the bent and formed products such as the stacked and side plates of the grand pianos of the present invention have the effects of reducing the manufacturing cost while ensuring good bendability. Have.

[Brief description of the drawings]

FIG. 1 is a partial perspective view showing a wooden board constituting a stack according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a state of stacking manufactured using a plurality of wooden board members of FIG. 1 before and after bending.

FIG. 3 is a plan view showing a state where a side plate is attached to the stack of FIG. 2;

FIG. 4 is a perspective view similar to FIG. 2 of a conventional unloading.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Unloading 2 Wood board material 2a Veneer veneer 2b Veneer veneer 3 Side plate

Claims (3)

[Claims] 1. A bent product of a grand piano formed of a plurality of wooden boards stacked and bonded to each other and bent to match the outer peripheral shape of the grand piano. A bent product of a grand piano, wherein at least one of the wooden boards is made of plywood. 2. The bent product of a grand piano according to claim 1, wherein all of the plurality of wood boards are each made of plywood. 3. The plywood has one core veneer whose grain extends in a direction orthogonal to a direction along the outer periphery of the grand piano, and each has a thickness smaller than the core veneer. ,
Characterized in that the core veneer is adhered to the front and back surfaces of the veneer veneer, and is composed of two veneer veneers whose grain extends in a direction along the outer periphery of the grand piano.
A bent product of the grand piano according to claim 1.